[luatex] Wildcard expansion by texlua on Windows

[Joseph Wright]

Hello all,

I wonder if the handling of wildcard arguments by LuaTeX running as
texlua is documented anywhere, and if it's controllable.

With LuaTeX, irrespective of platform, arguments are passed 'as is' to
Lua, so if we have a test.tex file

     \directlua{for _,v in ipairs(arg) do print(v) end}
     \end

and run

     luatex test.tex '*' -- macOS/Linux
     luatex test.tex *  -- Windows

we print "*". On the other hand, if we have test.lua file

     for _,v in ipairs(arg) do print(v) end

and try

     texlua test.lua '*' -- macOS/Linux
     texlua test.lua *   -- Windows

we get "*" on macOS/Linux and ... whatever is in the current directory
on Windows. If we use '*' there, that's *exactly* what gets shown - no
expansion, but also no loss of the ' chars (of course we can clean up).

I *think* that the only expansion is the same as e.g. dir would do -
only "*" and "?", and if there are no matches things are passed on as-is.

I can't see that this behaviour is documented anywhere, nor if it's at
all controllable.

Does anyone have any insight?

Joseph